This invention relates to fire-resistant articles, for example, fire doors, and is especially related to cores of such doors, particularly cores of the type adapted to be enclosed between sheet metal door edge and side face components.
One of the primary objectives of the invention is to provide a fire door of relatively light weight, and for this purpose, the invention contemplates the manufacture of a door core by a molding technique which provides a core which is not only of light weight but which is also of relatively high strength.
In accordance with another objective, the invention provides a technique for production of a fire door core which has adequate strength in the processing stages to withstand handling, treating and assembly of parts, even before the final curing of the core structure.